1. Field of the Invention
The present invention is a microfluidics-based cartridge for automated extraction of biological molecules from cells, spores, virions, their lysates, and other biological samples. The present invention is capable of isolating nucleic acids, proteins, and other biological macromolecules from less than 10,000 cells in 30 minutes.
2. Description of Related Art
Microfluidic apparatus and methods for the lysis of cells and/or separation of selected lysate components are known in the art. U.S. Pat. No. 6,287,831 B1 to Tai et al. discloses a cell lysis device in which micromachined electrodes spaced less than 100 micrometers apart on a silicon substrate are used to lyse cells. US 2007/0134809 (Cho et al.) discloses a microfluidic device for the concentration and lysis of cells or viruses in which lysis is accomplished by radiating magnetic beads in a reaction chamber with a laser. US 2004/0058423 A1 (Albritton et al.) discloses an apparatus for sequential lysis of selected adherent cells in which a single electric pulse of between 10 milliseconds and 10 microseconds is used to lyse cells and lysate is transferred into a microcollection device. U.S. Pat. No. 7,169,277 B2 to Ausserer et al. discloses a device that separates sample materials into different fractions using a combination of bulk flow for loading samples and electrophoretic separation of sample materials.
A microfluidic cartridge and associated method for selective lysis of and extraction of DNA from cell mixtures is disclosed in US 2005/0064598 A1 (Yuan et al.). The microfluidic differential extraction cartridge selectively lyses one of at least two populations of cells in a mixed sample using sonication at frequencies capable of lysing on cell type and not another. The differential extraction is based on the selective lysis of one cell type over another using, for example, sonication to selectively lyse one cell type and chemicals or heat to lyse a second cell type. The cartridge comprises a sample input chamber, a sonication lysis chamber, a means for separating lysed cells from intact cells, and a collection vessel to collect cell lysate. An additive, such as glass beads or chemicals can be added to the sonication chamber before cell lysis. The cartridge may comprise a mixing chamber to add and mix a solution into a cell lysate and a purification chip to purify and concentrate nucleic acid from the cell lysate.
The utility of existing microfluidic systems for cell lysis and isolation is, in some cases, limited due to high internal pressure drops required to achieve acceptable flow rates, capture and elution times, and bubble formation. The present invention overcomes these limitations by providing a capture chamber containing beads that bind the target species to be captured wherein the beads are maintained in a fluidized state.